Barometric pressure sensor and method for preparing same, and electronic device

Abstract

Disclosed are a barometric pressure sensor and a method for preparing the same, and an electronic device, which relate to the technical field of sensors. The barometric pressure sensor includes a base substrate, and a first capacitor provided on a side of the base substrate. The first capacitor includes a first bottom electrode provided close to the base substrate; a first insulating layer provided on a side of the first bottom electrode away from the base substrate; and a first top electrode provided on a side of the first insulating layer away from the base substrate. The first top electrode is provided with a first opening which is configured to expose the first insulating layer at a corresponding position. A dielectric constant of the first insulating layer may vary with different humidity environments, so that a capacitance value of the first capacitor varies.

1 . A barometric pressure sensor, comprising a base substrate, and a first capacitor provided on a side of the base substrate, wherein the first capacitor comprises:
 a first bottom electrode, provided close to the base substrate;   a first insulating layer, provided on a side of the first bottom electrode away from the base substrate; and   a first top electrode, provided on a side of the first insulating layer away from the base substrate, wherein the first top electrode is provided with a first opening which is configured to expose the first insulating layer at a corresponding position; and   wherein a dielectric constant of the first insulating layer may vary under different humidity environments, so that a capacitance value of the first capacitor varies.   
     
     
         2 . The barometric pressure sensor according to  claim 1 , wherein a surface of the first insulating layer away from the base substrate and a surface of the first top electrode close to the base substrate are in contact with each other. 
     
     
         3 . The barometric pressure sensor according to  claim 1 , wherein the first capacitor further comprises:
 a first cavity provided between the first insulating layer and the first top electrode, an orthographic projection of the first cavity on the base substrate at least partially overlaps with an orthographic projection of the first opening on the base substrate, and an area of the orthographic projection of the first cavity on the base substrate is greater than an area of the orthographic projection of the first opening on the base substrate.   
     
     
         4 . The barometric pressure sensor according to  claim 1 , wherein the barometric pressure sensor further comprises:
 a heating electrode insulated from the first bottom electrode and the first top electrode, respectively, an orthographic projection of the heating electrode on the base substrate does not overlap with an orthographic projection of the first bottom electrode on the base substrate and an orthographic projection of the first top electrode on the base substrate, and the orthographic projection of the heating electrode on the base substrate is within the orthographic projection of the first insulating layer on the base substrate.   
     
     
         5 . The barometric pressure sensor according to  claim 4 , wherein the heating electrode is provided on the same layer and made of the same material as the first bottom electrode, and the heating electrode is a closed structure surrounding the first bottom electrode; and/or the heating electrode is provided on the same layer and made of the same material as the first top electrode, and the heating electrode is a closed structure surrounding the first top electrode. 
     
     
         6 . The barometric pressure sensor according to  claim 4 , wherein in a first direction parallel to the base substrate, the barometric pressure sensor comprises a plurality of heating electrodes separated from each other, and the first direction is a direction from a center to an edge of the first insulating layer. 
     
     
         7 . The barometric pressure sensor according to  claim 1 , wherein the first opening has at least one of the following features:
 on a plane parallel to the base substrate, a plurality of first openings are evenly arranged on the first top electrode;   on the plane parallel to the base substrate, the plurality of first openings are arranged in an array along a row direction and/or a column direction;   a ratio of an area of an orthographic projection of the first opening on the base substrate to an area of an orthographic projection of the first top electrode on the base substrate is greater than or equal to 5% and less than or equal to 10%; and   a shape of the orthographic projection of the first opening on the base substrate comprises at least one of a sector, an ellipse, a polygon and an irregular shape.   
     
     
         8 . The barometric pressure sensor according to  claim 1 , wherein an orthographic projection of the first insulating layer on the base substrate covers an orthographic projection of the first bottom electrode on the base substrate and an orthographic projection of the first top electrode on the base substrate, respectively, and the orthographic projection of the first bottom electrode on the base substrate at least partially overlaps with the orthographic projection of the first top electrode on the base substrate. 
     
     
         9 . The barometric pressure sensor according to  claim 1 , wherein the barometric pressure sensor further comprises a second capacitor provided on the same side of the base substrate as the first capacitor, and the second capacitor comprises:
 a second bottom electrode, provided close to the base substrate;   a second cavity, provided on a side of the second bottom electrode away from the base substrate; and   a second top electrode, provided on a side of the second cavity away from the base substrate;   wherein the second cavity is a sealed cavity, and the second top electrode may deform under an action of external barometric pressure, so that a capacitance value of the second capacitor varies.   
     
     
         10 . The barometric pressure sensor according to  claim 9 , wherein the barometric pressure sensor further comprises:
 a third cavity, provided on a side of the second top electrode away from the base substrate; and   a third top electrode, provided on a side of the third cavity away from the base substrate;   wherein the second top electrode, the third cavity and the third top electrode constitute a third capacitor, and the third top electrode is provided with a second opening which is configured to communicate an external environment with the third cavity.   
     
     
         11 . The barometric pressure sensor according to  claim 10 , wherein the second opening has at least one of the following features:
 on a plane parallel to the base substrate, a plurality of second openings are evenly arranged on the third top electrode;   on the plane parallel to the base substrate, the plurality of second openings are arranged in an array along a row direction and/or a column direction;   a ratio of an area of an orthographic projection of the second opening on the base substrate to an area of an orthographic projection of the third top electrode on the base substrate is greater than or equal to 5% and less than or equal to 10%; and   a shape of the orthographic projection of the second opening on the base substrate comprises at least one of a sector, an ellipse, a polygon and an irregular shape.   
     
     
         12 . The barometric pressure sensor according to  claim 9 , wherein the first bottom electrode is provided on the same layer as the second top electrode. 
     
     
         13 . The barometric pressure sensor according to  claim 9 , wherein the second capacitor is provided between the first capacitor and the base substrate, and an orthographic projection of the first capacitor on the base substrate at least partially overlaps with an orthographic projection of the second capacitor on the base substrate. 
     
     
         14 . The barometric pressure sensor according to  claim 9 , wherein an orthographic projection of the second bottom electrode on the base substrate and an orthographic projection of the second top electrode on the base substrate both cover an orthographic projection of the second cavity on the base substrate, and the orthographic projection of the second bottom electrode on the base substrate at least partially overlaps with the orthographic projection of the second top electrode on the base substrate. 
     
     
         15 . The barometric pressure sensor according to  claim 10 , wherein an orthographic projection of the second top electrode on the base substrate covers an orthographic projection of the third cavity on the base substrate, the orthographic projection of the third cavity on the base substrate is within an outer contour of an orthographic projection of the third top electrode on the base substrate, and the orthographic projection of the second top electrode on the base substrate at least partially overlaps with the orthographic projection of the third top electrode on the base substrate. 
     
     
         16 . The barometric pressure sensor according to  claim 1 , wherein the barometric pressure sensor further comprises at least one of:
 a second insulating layer, provided between the first bottom electrode and the first insulating layer, wherein an orthographic projection of the second insulating layer on the base substrate at least covers an orthographic projection of the first bottom electrode on the base substrate; and   a third insulating layer, provided on a side of the first top electrode away from the base substrate, wherein the third insulating layer is provided with a third opening, and an orthographic projection of the third opening on the base substrate at least partially overlaps with an orthographic projection of the first opening on the base substrate.   
     
     
         17 . An electronic device comprising:
 the barometric pressure sensor according to  claim 1 ; and   a detection circuit, connected to the barometric pressure sensor, for determining an environment humidity around the barometric pressure sensor based on the capacitance value of the first capacitor.   
     
     
         18 . A method for preparing a barometric pressure sensor, comprising:
 providing a base substrate;   forming a first bottom electrode, a first insulating layer and a first top electrode sequentially on a side of the base substrate, wherein the first bottom electrode, the first insulating layer and the first top electrode constitute a first capacitor, the first top electrode is provided with a first opening which is configured to exposing the first insulating layer at a corresponding position, and a dielectric constant of the first insulating layer may vary with different humidity environments, so that a capacitance value of the first capacitor varies.   
     
     
         19 . The method according to  claim 18 , wherein the forming the first bottom electrode, the first insulating layer and the first top electrode sequentially on the side of the base substrate, comprises:
 forming the first bottom electrode on the side of the base substrate;   forming a first insulating layer pattern on a side of the first bottom electrode away from the base substrate by a first patterning process;   performing plasma bombardment on the first insulating layer pattern to form nanofibers in the first insulating layer pattern, and obtaining the first insulating layer; and   forming the first top electrode on a side of the first insulating layer away from the base substrate.   
     
     
         20 . The method according to  claim 19 , wherein after the obtaining the first insulating layer, the method further comprises:
 forming a first sacrificial layer material on the side of the first insulating layer away from the base substrate, wherein an orthographic projection of the first sacrificial layer material on the base substrate at least covers an orthographic projection of the first insulating layer on the base substrate; and   wherein the forming the first top electrode on the side of the first insulating layer away from the base substrate, comprises:   forming the first top electrode on a side of the first sacrificial layer material away from the base substrate by a second patterning process;   forming a first cavity and a first sacrificial layer between the first insulating layer and the first top electrode by etching the first sacrificial layer material through a first opening in the first top electrode, wherein an orthographic projection of the first cavity on the base substrate at least partially overlaps with an orthographic projection of the first opening on the base substrate, and an area of the orthographic projection of the first cavity on the base substrate is greater than an area of the orthographic projection of the first opening on the base substrate.